Rotary dust separator impeller



D ec. 10, 1940. sTlG G=soN sYLvAN 21,224,617

ROTARY DUST SEPARATOR IMPELL'ER A Original Filed April 7, 1936 l :ny am@www1/701e y @WL/WM fm2/yf? Patented Dec. 10, 1940 UNITED sTATEs PATENTOFFICE to American Air Filter Company, Inc., Louisville, Ky., acorporation of Delaware Original application Api-ii mismas, serial No.

73,142. Divided and this application April 27,

1938, Serial N0. 204,507

1 Claim.

This invention relates to improvements in impellers for rotary dustseparators of the character described in my copending application SerialNo. '13,142 of which this is a division.

The principal object of the invention is to simplify the structuraldesign and reduce the manufacturing cost of impellers for rotary dustseparators.

The invention is illustrated in the accompanying drawing, wherein:

Figure 1 is a front elevation of an impeller constructed in accordancewith my invention;

Figure 2 i-s a side view thereof with the lower half in section and theupper half in elevation;

and

Figure 3 is a rear elevation.

The illustrated impeller, which is iixedly secured to a rotatable driveshaft 2, includes a conically shaped hub 3, an annular disc I, a.

series of blades 5 and a band 8. The hub I is xedly secured to the shaft2 while the annular disc 4 is similarly secured to the hub 3 andarranged to extend radially therefrom. The annular voutward pull exertedon the disc, as a result of its rotation, increases from its peripheryinwardly to its points of securement to the hub. Accordingly it isdesirable to increase the thickness of the dise from its peripheryinwardly in order vto provide the requisite strength and at the sametime keep the weight of the disc at a minimum. Heretofore the disc-hasbeen cast in such form. In accordance with this invention the sameresult is achieved in a simpler manner and'at less expense by rivetingor otherwise securing together a requisite number of plates of differentoutside diameters. The vnumber of plates used will depend upon thestrain to be encountered and the thickness of each plate. For the mostpart three to five plates of suitable thickness have been foundsufficient for a wide range of impeller speeds and diameters but adifferent number may of course be used as the occasion may require. Withthree plates of dierent diameter the strain in the outer section of thedise is carried by the largest plate, in the intermediate sectionthereof by the two larger plates and in the inner section by all three.The plate of largest diameter is preferably placed on (Cl. E30-134) theair flow side of the disc as a whole in order to provide a at seatingsurface for the blades 5.

The blades 5 are fixedly secured to the disc and arranged to projectlaterally therefrom across the air flow. While the blades may be shaped5 and arranged as desired. they are shown as of flat shape and ofstraight radial arrangement. The blades also should be inclined to thedisc in such manner as to cause particles precipitated on them duringrotation to move toward that 10 side of the air flow from which theparticles are to be removed. In the structure illustrated the particlesare to be removed from the disc side of the air flow and consequentlythe blades are in clined forwardly across the air fiow from the disc 154 to the band 6 so that the band edges of the blades lead the'dsc edgesthereof in the direction of rotation.

The band 6, which is secured to the adjacent side edges of the blades,operates to stiiien the 20 blade structure Ias a whole. It has also beenfound to improve the blower characteristics of the device and for thatreason is made wide enough to cover the side edges of the bladescompletely from their inlet to their outlet edges. 25 In this characterof device, it is desirable that the flow area at the outlet edges of theblades be not greater and preferably smaller than the area at the inletedges thereof. For that reason the band is made cone shaped and arranged30 to approach the disc as it extends outwardly so as to produce anoutwardly converging centrifuging passage, the slope of the banddepending upon the inlet-outlet area ratio desired.

I claim:

An impeller of the class described comprising: a hub having a securingflange; a unitary annular disc iixedly mounted on said hub against saidange, said disc being composed of a series of at least three plates ofdifferent diameters o arranged in face-to-face relation and secured tosaid flange and to each other, the diameters of said platesprogressively decreasing in one direction from the largest plate of theseries to the smallest plate thereof; and a series of fluid- 45propelling blades xedly secured torsaid disc.

STIG G: SON SYLVAN.

